The adsorption characteristics of transition metal (TM) adatoms on olympicene, a graphene-like molecule consisting of five rings of which four are benzene-like rings, are analyzed by means of first principles calculations. The electronic structures and magnetic properties of 3d transition metals on olympicene were investigated in the framework of generalized-gradient approximation using relativistic density functional theory. Our calculations were based on full-potential local orbital (FPLO) method. Stable structure and total energies were obtained. Relaxed TM@Olympicene molecules, unlike the pure organic olympicene, were partially buckled. Binding, energy calculations showed high stability for Ni@Olympicene whereas Mn did not bind to olympicene surface. Electronic charge transfers were consistent with Pauling electronegativities. The related HOMO-LUMO gaps decreased with respect to pure olympicene. Our calculated total and TM spin magnetic moments indicated that TM@Olympicene were strongly magnetized. Orbital polarization correction (OPC) were also used in order to get an upper estimation for orbital magnetic moment of all 3d atoms. Fe@Olympicene shows highest orbital moment of 0.18 AB. The Atoms in Molecules (AIM) approach was used to analyze the nature of TM-C bonds in TM@Olympicene complexes. The results show the TM C bonds have a degree of covalency in their interactions. (C) 2017 Elsevier B.V. All rights reserved.